engine light question

my engine light came on when my truck turned over 200,000 miles and i would like to shut it of.my question is there is a white junction box under the dash with two plugs and one is open and i heard if i unplugged it from the one it's in now and plugged it in the other it would reset.is this right or do i have to use the scanner port under the hood to somehow reset it.the truck runs great and i don't want to do anything that will mess up the FI because i know nothing about it.thanks in advance for any help.



oh yea it's a 26i if that matters